The invention described herein pertains to a sulky for a self-propelled lawn mower for carrying an operator in a standing position safely behind the mower, thus eliminating the need for the operator to walk behind the mower.
Devices for attachment to self-propelled power lawn mowers, allowing a standing operator to be carried with the mower, have been in use for many years. An early example may be seen in U.S. Pat. No. 2,955,835 issued Oct. 11, 1960 to Chouinard. The apparatus, typically called a "sulky," consists of a platform mounted between two wheels that is connected to the mower by a tow bar. Chouinard's tow bar is connected to the mower by a universal joint allowing the sulky to move in all directions relative to the mower during operation. Another sulky apparatus is illustrated in U.S. Pat. No. 5,004,1991 to Velke; it employs a platform covering a single wheel located between the foot plates for the operator's feet. The platform is pivotally connected to one end of the tow bar along a vertical axis, allowing free rotation of the platform horizontally. The other end of the tow bar is pivotally connected to the mower along a horizontal axis to allow the platform and tow bar to move up and down with respect to the mower. Still another sulky apparatus is described in U.S. Pat. No. 5,413,364 issued May 9, 1995 to Hafendorfer; this sulky provides another pivoting action as it permits the sulky to pivot about an axis that is aligned with the length of the tow bar. Pivoting of the sulky about this axis permits the sulky to accommodate uneven ground.
None of the sulky apparatus typified by the above references, however, addresses the problem of too much pivoting of the sulky away from the plane of the mower, pivoting that could result in the dislodgment of the operator or overturn of the entire sulky.
The aforementioned co-pending and commonly assigned U.S. patent Ser. No. 08/916,492 describes a riding attachment that does address this concern. More specifically, the application describes a riding attachment adapted to be connected to a self-propelled lawn mower for carrying a standing rider/operator and comprising a tow bar assembly, a riding assembly, and a pivot limiting element that limits the pivoting of the riding assembly out of the plane of the mower to a predetermined limit angle. The tow bar assembly is pivotally connected to the mower for pivoting about a first axis essentially parallel to the mower plane and essentially transverse to the direction of movement of the mower during operation. The tow bar assembly is constrained against pivoting with respect to the mower about an axis essentially vertical. The riding assembly, including a platform for supporting the standing operator, is pivotally connected to the tow bar assembly for pivoting about a second axis essentially parallel to the mower plane and to the direction of movement of the mower. The riding assembly is also constrained against pivoting about an axis essentially vertical with respect to the tow bar assembly. The pivot limiting element is associated with the tow bar assembly and limits the pivoting of the riding assembly about the second axis so that the riding assembly is prevented from turning over when severe uneven terrain is encountered.
However, the invention described in the co-pending application has some attendant disadvantages. Most importantly, since the riding assembly is constrained against pivoting about an axis essentially vertical with respect to the tow bar assembly, operators of gear drive motors may encounter some difficulty in turning with the mower. This problem arises because when the riding assembly is constrained from pivoting relative to the tow bar assembly, the mower must carry the weight of the operator through the turn. Thus, in mowers employing gear drives, as opposed to hydrostatic drives, the belts which grip the wheel axles may slip when the operator attempts a sharp turn due to weight of the operator, making sharps turns difficult, if not impossible, to perform.
It is therefore a paramount object of the present invention to provide for a sulky apparatus that has a riding assembly that is connected to a tow bar assembly such that the riding assembly can pivot relative to the mower plane but will not overturn, and such that the operator can easily turn the mower.
Other important objects will become clear to those skilled in the art upon a reading of the description accompanied by the appended drawings.